“From Bilateral Trade to Centralized Markets: A Search Model for Commodity Exchanges in Africa,” with Pellegrina, H. S., (2021).
Several African countries have recently centralized their agricultural markets by launching a commodity exchange. What will be the impact of such a move? Who will be the winners and the losers? We develop a simple search model to study the impact of introducing a commodity exchange in a village economy where traders and farmers exchange on a bilateral basis. We study the efficiency gains from moving from the status quo to a trading regime where farmers have the option of selling their produce to a commodity exchange. We describe how the gains from trade are distributed between farmers, traders and the commodity exchange itself. We show that a dual economy where farmers sell both to the bilateral and the commodity exchange can exist in equilibrium, and that forcing all farmers to sell into the commodity exchange can make some farmers worse off.
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“Price Information, Inter-Village Networks, and 'Bargaining Spillovers': Experimental Evidence from Ghana,” with Hildebrandt, N., Romagnoli, G., and Soldani, E., (2020).
Through a randomized experiment and detailed data on communications among farmers, we identify the impact of text-messages-based commodity price information on rural farmers’ revenues. The intervention affected prices received by farmers in two ways: (1) a long-lasting increase (9%) for treated farmers, and (2) substantial indirect benefits for certain control group farmers, which cannot be explained by classical informational spillovers. We discuss a novel mechanism of bargaining spillovers which can explain such positive externalities, even in the absence of information sharing between the treatment and control groups. Our results highlight the importance of accounting for longer-run spillovers and the potential of ICT interventions in emerging markets.
Nyarko, Y., Schotter, A., & Sopher, B. (2006). On the Informational Content of Advice: A Theoretical and Experimental Study. Economic Theory, 29(2), 433-452.
This paper examines the market for advice and the underlying perception that advice is useful and information…
Nyarko, Y., & Schotter, A. (2002). An Experimental Study of Belief Learning using Elicited Beliefs. Econometrica, 70(3), 971-1005. (See data for this paper).
This paper investigates belief learning.
Nyarko, Y., & Schotter, A. (2000). Comparing Learning Models with Ideal Micro & Experimental Data Sets. New York University.
This paper compares three learning models. The models compared are the Reinforcement Learning Model of Erev and Roth, the EWA model of Camerer and Ho and a Belief Learning model in which beliefs are elicited from subjects using a proper scoring rule…